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TO ALL PERSONS TO WHOM THESE PRESENTS SHALL COME: i

Be it known that I, WILLIAM D. WHITMORE, of Boston, in the county of Suffolk, and State of Massachusetts, have made a new and useful invention having reference to `metallic packed Piston for Steam or other Engines; and I do hereby declare the same to be fully described in the following specification, and represented in the accompanying drawings, of which Figure 1 is a side elevation; and

Figure 2, a longitudinal section of one of my improved pistons.

Figure 3 is a section of its head, taken in aplane at right angles with the axis of its rod, and through the ring-sections, wedges, and springs, to be hereinafter explained. l

The piston on which my invention is based is the well-known fBarton piston, which has a series of ringseotions or annular arcs arranged in the circumference of the pistonshead, and with their ends against wedges, forced outward or in radial directions by one or more springs. In constructing such a piston it has' been customary to arrange its ring-sections and their wedges between and against two circular plates, one fastened to the piston-rod, andthe other movable thereon, the whole being so as to render it necessary to remove the whole ofthe piston from the engine cylinder in order to remove any or all of the ring-sections and wedges from the piston-head, or to apply any or all of themA thereto, as circumstances may require. This removal of the piston from the cylinder necessitates the disconnection ofthe piston from the cross-head, or mechanical device to be moved by it. This oftentimes is a very inconvenient as well as a laborious operation, which it is the object of my invention to avoid, as with my improvement in the construction of the piston, the rod with its cap-plate may be left within the cylinder, without disconnection from the cross-head, whenever it may be necessary to remove the packing and its wedges and springs, they being taken in a connected state from` the piston.

In the drawings, A denotes the piston-rod, provided with a circular cap-plate, B. Against this capi-plate is placed a cylindrical box or case, C, closed at its front and open at the end next the cap-plate. This box is connected with the cap-plate by screws, ad a, which go through the head of the box andscrew into projections, b b b, from the capplate. An inner end view of the cap-plate, with such projections, is shown in Figure 4. An annular groove, c,- is made in the circumference of the box or case C, and between its two extremities. Four, or any other suitable number of openings, o?, lead from the groove radially into the interior space or chamber e of the case, each of such openings being for the reception and support of one of a series of sliding wedges, ffff,

arranged as represented. There is a spring, g, to press each wedge outwardly and against the contiguous ends of two ring-sections, L L. The groove c is filled with these ring-sections,`and the wedges arranged together and formed as shown'in lig. 3. A shank, z', extends from each of the wedges through its spring, and a projection, k, extending from the case, such projection serving as a guide to the shank, and to aid in keeping the wedge and its spring in place. By dctaching the case C from the plate B, the former, with the packing-ring sections, their operative wedges and springs, can easily be removed from the cylinder, and leave the head .B and pistonrod A therein and connected with the cross-head. My invention is calculated for use in locomotive and stationary engines, whose cylinders are so situated or connected with machinery as to require, for removal of their piston, the detachment of that head through which the-piston-rod does not travel.

I make no claim to a piston made with ring-sections, and wedges arranged between such sections, and pro' vided .with one or more springs for forcing thewedges forward, so as to press the ring-sections against the bore of the cylinder, such being the construction of the well-known Barton piston. Nordo I claim arranging a metallic packing-ring in a groove madein and about a piston-head, so that the ring may be supported on cach of its Hat sides bythe sides of the'groove rather than against the cap-plate of thepiston.

I claim my improved ring-section and wedge-piston as made, not only with its ring-sections and theirwedgcs Wholly within and supported by a case, C, separatefrom and to be attached to the cap B by screws, but as having the cap B applied to the piston-rod A, the whole being substantially as and for the purpose hereinbeforc'- set forth.

WM. D.v WHITMORE.

Witnesses:

R. H. EDDY, F, P.' HALE, Jr.' 

